What is the sum of the arithmetic series: s10 = -20, d = 4, a1 =?

first term a1 is -40.

Step-by-step explanation:

in an arithmetic series,

sum of first term terms (S10) = -20

Common difference (d) = 4

first term (a)= ?

number of terms (n)= 10

now,

S10 =( n÷2) [a1 +(n-1) d]

or, -20 = (10÷2) [a1 + (10-1) 4]

or, -20 = 5 ( a1 + 36)

or, -4 = a1 + 36

or, a1 = -40

hello from mrbilldoesmath!

answer:   x (x+6)^2, choice b

discussion:

factor x out of the equation:

x^3 + 12x^2 + 36x = x (x^2 + 12x + 36).

note that 6+6 = 12 and 6*6 = 36 so the above factors into:

x (x+6)^2

which is choice b

you,

mrb

you bought 31 v bucks

step-by-step explanation:

25+6=31